are you sure its engine knock>>>

It's definitely a knock, and seperate from the 'valve tick' that we hear at idle or during acceleration when the engine is cold. I've heard pinging before, and this is not that either. It can best be described as sounding similar to a rod knock, but not quite as intense.

The car makes a funny grinding, knocking noise around 1.5k-2.5rpm>>>

Yeah, you've got it.

I have always thought that my engine was worn out because of negligience in changing oil but it seems there are other ppl with this "problem">>>

We should give everyone w/ a 5th Accord a little project. Go out, lift your hood, start your engine, rev it up and see if you got it too! We might be surprised...